Satellite receiving system with transmodulating outdoor unit

ABSTRACT

A home satellite receiving system employs a transmodulating outdoor unit (ODU) that tunes to multiple signals, demodulates those signals into streams of data packets, and filters the streams of data packets to select data packets pertaining to viewer-specified programs. The ODU then constructs an integrated bitstream from the selected data packets and modulates that bitstream for transmission to an indoor IRD. This allows transfer of multiple programs from different satellite sources to the indoor IRD over a single coaxial cable. The indoor IRD reconstructs the packet stream timing for the viewer-specified programs from the integrated bitstream.

TECHNICAL FIELD

[0001] This invention relates to architectures for home digitalsatellite receiving systems.

BACKGROUND

[0002] Home satellite receiving systems have grown in popularity overthe years. People living in rural areas were early adopters, as thesepeople were often underserved by cable and regional broadcast networks.They mounted large dish receivers in their fields or backyards to enablesatellite reception of a broader selection of programming. Astransmission technology improved, the dish size decreased, paving theway for wider adoption in residential and urban areas. The dishfunctions as a passive reflector to focus signals received from thesatellite onto a low noise block (LNB) element. Signals are transmittedin the microwave range of 11.7 to 12.2 GHz, and once received, aretranslated to multiple transponder frequencies ranging from 950 to 1450GHz.

[0003] Early home satellite receiving systems were equipped with onetuner to tune to one transponder. The tuner resided in an indoor unit,often referred to as the integrated receiver/decoder (IRD). The IRDallowed the viewer to select a satellite polarity and a transponder andreceive one or more programs carried by the transponder. To choose adifferent program not in that transponder, the IRD-based tuner may needto select a new polarity so that it could tune to the correcttransponder for the desired program.

[0004] With the growth in popularity of personal video recorders (e.g.,digital video recorders, such as UltimateTV®-brand system from MicrosoftCorporation), some satellite receiving systems are now equipped withmultiple tuners. This allows the viewer to watch one program whilerecording another. The tuners are capable of tuning to differenttransponders independently of each other, thereby enabling reception ofmultiple signals. The signals are conducted from the outdoor receivingdish to the indoor IRD via multiple cables, one for each tuner. As anexample, the UltimateTV®-brand system from Microsoft Corporation isequipped with two tuners, and two coaxial cables are employed tointerconnect the satellite receiver with the system.

[0005] It would be an improvement, however, if home satellite receivingsystems could be equipped with multiple tuners, yet not require suchcumbersome cabling.

SUMMARY

[0006] A home satellite receiving system employs a transmodulatingoutdoor unit (ODU) that aggregates the multiple signals received by asatellite receiver into an integrated bitstream, which can then betransmitted over a single coaxial cable to the indoor IRD. In thedescribed implementation, the ODU has multiple tuners to tune tomultiple satellite signals. The ODU demodulates those signals intorespective streams of data packets and selects subsets of the datapackets that belong to viewer-specified programs, while filtering outunwanted data packets. The ODU then constructs an integrated bitstreamfrom the selected data packets and modulates that bitstream fortransmission to the indoor IRD. This facilitates transfer of multipleprograms from different satellite sources over a single coaxial cable tothe indoor IRD. The indoor IRD reconstructs the packet stream timing forthe viewer-specified programs from the integrated bitstream.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 illustrates a home satellite receiving system in which atransmodulating outdoor unit (ODU) may be implemented.

[0008]FIG. 2 is a block diagram of the transmodulating ODU.

[0009]FIG. 3 is a flow diagram of an exemplary process for receivingsignals from multiple satellites and producing a single data stream forinput to an in-home IRD.

DETAILED DESCRIPTION

[0010] The following discussion is directed to a home satellitereceiving system equipped with an outdoor unit (ODU) that is capable ofconcurrently receiving multiple signals from different satellite sourcesand/or polarities of one satellite and producing a single data streamthat can be transmitted to an indoor integrated receiver/decoder (IRD)over a single coaxial cable. The indoor IRD demodulates the data streamand routes the data to other devices for display and/or storage. Byequipping the home satellite receiving system with the transmodulatingODU, the indoor IRD can be manufactured more simply, thereby reducingthe costs of IRDs.

[0011] The home satellite receiving system is described in the contextof receiving digital video content. Representative video contentincludes such things as movies, television programs, commercials, liveevents, and so on. While the system is described as receiving videocontent, it can be used to record other forms of streaming content, suchas audio.

[0012] Exemplary Environment

[0013]FIG. 1 shows an exemplary environment 100 in which a homesatellite receiving system 102 can be implemented. Satellite receivingsystem 102 is illustrated as residing at a viewer's home 104. Asatellite broadcaster 110 has a broadcasting system 112 that packagesthe video content into digital packets for transmission over a satellitenetwork. The video content originates from a live feed received at thebroadcaster 110, or from stored content kept on storage disks 114. Anuplink transmitter 116 transmits the stream of packets as a modulatedsignal to one or more orbiting satellites, represented by satellites120(1), 120(2), and 120(3). The target satellite retransmits themodulated signal to the home satellite receiving system 102.

[0014] The home satellite receiving system 102 has a satellite receiver130 that is mounted outside of the viewer's home 104 to receive thesignals from the multiple satellites 120(1)-120(3). Each satellitetransmits signals on two different polarities: right hand polarity andleft hand polarity. In a three satellite architecture, the homesatellite receiving system 102 could be called upon to receive up to sixdifferent signals.

[0015] The satellite receiver 130 has a passive reflector dish 132 thatreflects satellite signals received from the satellites 120(1)-120(3)onto a low noise block (LNB) element 134. The satellite receiver 130passes the multiple signals over corresponding conductors or cables 136to an outdoor unit (ODU) 140. As its name implies, the outdoor unit 140is mounted externally of the viewer's home 104 and proximal to thereceiver 130 so that the cables 136 are relatively short in length. TheODU 140 may be located, for example, on the back of the dish 132 ormounted at or near its supporting base.

[0016] The ODU 140 tunes to multiple signals, demodulates the signals torecover the data packets, and filters the data packets based on theirprogram identifier (PID). The ODU 140 then statistically multiplexesmultiple packet streams for multiple programs into a single data streamand modulates the single data stream. Because the ODU 140 is capable ofdemodulating multiple signals, producing a single data stream, and thenremodulating that data stream for transmission to the IRD, the ODU isreferred to as a “transmodulating” device.

[0017] The transmodulating ODU 140 transmits the modulated data streamover a single cable 142 to one or more IRDs 150 inside of the viewer'shome 104. The IRDs 150 demodulates the stream of packets and routes thepackets to a set-top box 160 (or other decoder unit) directly, or via ahome network (not shown), for display on a television 162. Multiple IRDsmay be used in a viewer's home to facilitate satellite reception controlfrom different venues and televisions in the home.

[0018] The viewer enters commands to control satellite reception via theset-top box 160 using, for example, a remote control handset. Theset-top box 160 passes these commands to the IRD 150, which transmitsthem to the transmodulating ODU 140 over the cable 142, or some otherconductor (not shown). Based on the viewer command, the ODU 140 tunes tothe appropriate transponder frequency of a band polarity from adesignated satellite, and filters the demodulated packets to obtain thepackets for the viewer-designated programs.

[0019] Exemplary ODU

[0020]FIG. 2 shows an exemplary implementation of the transmodulatingODU 140. It has multiple inputs to receive multiple signals from thesatellites. In the illustrated implementation, there are six inputs202(1), 202(2), . . . , 202(6) to receive two polarities from each ofthe three satellites 120(1)-120(3). The inputs are coupled to a switch204, which connects the inputs to various tuner/demodulator pairs206(1), 206(2), . . . , 206(N).

[0021] Each tuner/demodulator pair has a tuner 208(1), 208(2), . . . ,208(N) and an associated demodulator 210(1), 210(2), . . . , 210(N). Thetuner 208 tunes to individual transponder frequencies as directed byviewer-entered commands. The viewer-entered commands are sent to the ODU140 from the IRD 150, and routed to a processor 212, which directs thetuners 208(1)-208(N) to tune to the desired transponder frequencies.

[0022] As the tuned signal is received, the associated demodulator210(1)-210(N) demodulates the signal to recover a bitstream. Oneexemplary demodulated bitstream contains data coded at 30 Mbits/second.The bitstream consists of digital data packets, as represented bypackets 214. Each packet contains a header, content (video, audio, etc.in compressed or non-compressed form), redundancy, and so on. Eachpacket header includes the program identifier (PID) 216 that associatesthe individual packets with a program (e.g., television show, on-demandmovie, newscast, sports event, etc.).

[0023] The number of signals that the ODU 140 can concurrently receivedepends on the number of tuner/demodulator pairs 206. There is onetuner/demodulator 19 pair 206 for each signal. For instance, to receivesix different signals simultaneously from the three satellites120(1)-120(3), the ODU 140 is equipped with six tuner/demodulator pairs206 (i.e., N=6).

[0024] The demodulated streams of packets are passed from thetuner/demodulator pairs 208(1)-208(N) to associated demultiplexers220(1)-220(N) for selection of one or more individual programs. There isone demultiplexer 220 for each tuner/demodulator pair 206. Eachdemodulated packet stream typically contains packets for multipleprograms. For each stream, the associated demultiplexer 208 selectspackets for requested programs based on the PID 216 found in the header.

[0025] The processor 212 instructs the demultiplexers 220 of the desiredPID 216 in response to a program selection made by the viewer. Thisprogram selection is conveyed to the processor 212 from the IRD 150. Byselecting the packets with the appropriate PID, the demultiplexers 208operate as a filter to filter out unwanted data packets having PIDsassociated with programs that are not selected by the viewer. Thisreduces the bitstream density, thereby improving bandwidth downstream onthe single cable 142. For example, the demultiplexing process mightreduce the bitstream from, say, 30 Mbits/second to 5 Mbits/second.

[0026] The selected packets are time stamped with a local time by timestamping units 222(1)-222(N). The localized time stamp will be used toreconstruct the packet stream timing for various programs at the IRD150, as described below. Until this point in the transmodulatingprocess, the packets in individual streams are handled with constantbroadcast delay. Once they are demultiplexed and time stamped, however,the packets are handled at variable rates until reconstructed at theindoor IRD 150. The variable delay between packets allows the multiplestreams to be flexibly integrated into a common stream for transmission.

[0027] The selected packets are stored in respective queues 230(1),230(2), . . . , 230(N). There is one queue 230 for eachtuner/demodulator pair 206. Through this point in the processing, theODU 140 has maintained the data packets in their respective streams.That is, queue 230(1) holds the filtered packets received via tuner208(1) and demodulated by demodulator 210(1). Similarly, queue 230(2)holds the filtered packets received via tuner 208(2) and demodulated bydemodulator 210(2), and so on. The packets from different streams arepassed into their respective queues at different rates. The queues 230temporarily store the packets from different streams for subsequentconstruction of an integrated bitstream having packets from multipleprograms.

[0028] The queued packets from queues 230(l)-230(N) are assembled by amultiplexer 240 into a single data stream. The multiplexer 240effectively aggregates data packets from different programs into acommon stream. The multiplexer 240 chooses the packets from the variousqueues for assembly in the data stream according to any one of manydifferent selection criteria. For instance, the multiplexer 240 mightchoose packets from the various queues according to the local time stampon the packets. Alternatively, the multiplexer may iteratively take onepacket at a time from each queue in a rotational cycle. In still anotherimplementation, the ODU may implement a FIFO (first in first out)scheme. Another possibility is for the ODU to prioritize requests andselect packets in accordance with the priority assigned to the requestedprogram. Packets might also be selected based on queue depth by takingpackets from the queue with the most packets, or selecting packets whenindividual queues reach a predetermined number of packets.

[0029] The demultiplexer 240 outputs the single bitstream to aremodulator 250, which modulates the bitstream for transmission to theIRD 150. The remodulator 250 can utilize a conventional modulationtechnique, such as QAM, COFDM, QPSK, 8PSK, and the like. The single datastream can be modulated at the same or different frequency as thesatellite signal originally received by the ODU. The modulated bitstreamis passed over the coaxial cable 142 to one or more IRDs 150. In thismanner, the IRDs 150 receive a modulated bitstream as expected from thesatellite receiver. However, this modulated bitstream contains packetsfrom multiple satellite signals, as opposed to just one.

[0030] The IRD 150 has a demodulator 252 to demodulate the bitstreamreceived from ODU 140. The IRD 150 then reconstructs the timing of thepackets for various programs using the local time stamps applied by theODU. This reconstruction restores the intended delay between packets ina common program stream. The IRD 150 is also coupled to supplyinstructions to the ODU, either via the cable 142 or another connection(wire-based or wireless). The instructions pertain to such operations astuning and program selection. The instructions are handled by theprocessor 212. Additionally, the IRD can provide feedback to improve ormodify transmission of the modulated signal over the cable 142. Theprocessor 212 receives the feedback and makes adjustments to theremodulator 250.

[0031] One beneficial feature of the ODU 140 is the ability to selectprograms individually, rather than being constrained to selectingtransponder polarities. By demodulating the signal and selecting packetsbased on program identifiers (PIDs), the ODU is able to filter unwantedpackets and thereby increase the bandwidth efficiency on the coaxialcable 142.

[0032] Another advantageous feature of the system is that the complexdemodulation of the satellite signals is handled at the ODU 140, ratherthan the IRD 150. The ODU can then implement a different, less complexdemodulation scheme for the local modulation performed by theremodulator 250. For instance, the remodulator 250 may use a simplemodulation scheme, such as QSPK, to transmit the data to the IRD. TheIRD can thus be designed with less complex demodulation components,resulting in a less expensive device. This allows consumers to purchasemultiple IRDs for their home entertainment architecture, all of whichcan be supported by a single ODU 140.

[0033] Another advantage of the system is that it affords a controlledsignal environment, which is not susceptible to interference. A weaksatellite signal can be decoded close to the initial receiver, therebyimproving recovery of the signal. This permits use of simpler and lesssophisticated ODU tuning and demodulator components. Additionally,adjusting for any changes in the modulation scheme used by the satelliteinvolves merely replacing the ODU, rather than the in-home IRD(s).

[0034] Satellite Reception and Transmodulation

[0035]FIG. 3 shows an exemplary process 300 for operating the homesatellite receiving system to receive signals from multiple satellitesand produce a single data stream for input to an in-home IRD. Theprocess will be described with reference to the implementation of thetransmodulating ODU 140 described in FIGS. 1 and 2. The process 300 isimplemented by a combination of software, firmware, and hardware. In thecase of software and firmware, process 300 represents a set ofoperations that may be implemented as computer-executable instructionsthat can be executed by one or more processors.

[0036] At block 302, the satellite receiving system 102 receives one ormore satellite signals from one or more satellites 120. These signalsmay be from different polarities of the same satellite or from differentsatellites. The multiple tuners 208 in the ODU 140 tune to particulartransponder frequencies in the one or more signals.

[0037] At block 304, demodulators 210 demodulate the signals received atthe transponder frequencies. The demodulation results in a stream ofpackets for each received signal. At block 306, associateddemultiplexers 220 demultiplex each stream of packets to select certainpackets, and filter others, based on the program identifier (PID)contained in the packets. The desired PIDs are conveyed to the ODU 140from the IRD 150 based upon user input. The selected packets are timestamped with a local timestamp (block 308).

[0038] At block 310, the streams of time stamped packets are storedtemporarily in respective queues 230. At block 312, the multiplexer 240multiplexes the queued packets from the different streams into a singledata stream. The remodulator 250 then modulates the single data stream(block 314). The data stream may be modulated using a differentmodulation scheme and at a different modulation frequency than that ofthe original signal received from the satellite. At block 316, the ODUtransmits the modulated single data stream over the cable 142 to the IRD150.

[0039] Conclusion

[0040] Although the invention has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the invention defined in the appended claims is not necessarilylimited to the specific features or acts described. Rather, the specificfeatures and acts are disclosed as exemplary forms of implementing theclaimed invention.

1. A home satellite receiving system comprising: a satellite receiver toreceive multiple signals from one or more satellites; an intermediaryunit to aggregate the multiple signals received by the satellitereceiver into a single bitstream for transmission over a localconnector; and a decoding unit connected to receive the single bitstreamfrom the local connector and to decode the single bitstream.
 2. A homesatellite receiving system as recited in claim 1, wherein the decodingunit comprises an integrated receiver/decoder (IRD).
 3. A home satellitereceiving system as recited in claim 1, wherein the decoding unit isconfigured to reside indoors and the intermediary unit is configured toreside outdoors and proximal to the satellite receiver.
 4. A homesatellite receiving system as recited in claim 1, wherein the localconnector comprises a coaxial cable.
 5. A home satellite receivingsystem as recited in claim 1, wherein the intermediary unit comprisesmultiple tuners.
 6. A home satellite receiving system as recited inclaim 1, wherein the intermediary unit comprises: multiple demodulatorsto demodulate ones of the signals into associated streams of packets; adata aggregator to construct the single bitstream from the streams ofpackets; and a remodulator to modulate the single bitstream fortransmission to the decoding unit.
 7. A home satellite receiving systemas recited in claim 6, wherein the intermediary unit further comprises afilter to remove unwanted packets prior to construction of the singlebitstream.
 8. A home satellite receiving system as recited in claim 6,wherein the intermediary unit further comprises a filter to filterpackets based on program identifiers in the packets that associate thepackets with programs.
 9. A home satellite receiving system as recitedin claim 6, wherein the intermediary unit further comprises a time stampcomponent to timestamp the packets used to construct the singlebitstream.
 10. A home satellite receiving system comprising: a receiverto receive multiple satellite signals; and an outdoor unit connected tothe receiver to demodulate the satellite signals into multiplecorresponding streams of data packets, the outdoor unit being configuredto form a single bitstream containing the data packets from the multiplestreams and modulate the single bitstream for transmission to an indoordevice.
 11. A home satellite receiving system as recited in claim 10,wherein the outdoor unit demodulates the satellite signals according toa first modulation technique and modulates the single bitstreamaccording to a second modulation technique that is different than thefirst modulation technique.
 12. A home satellite receiving system asrecited in claim 10, wherein the outdoor unit comprises: multiple tunersto tune to the signals; and multiple demodulators, each demodulatorbeing associated with a corresponding tuner to demodulate the signalreceived by the corresponding tuner.
 13. A home satellite receivingsystem as recited in claim 10, wherein the outdoor unit facilitatesselection of the data packets to be included in the single bitstreambased upon a program identifier.
 14. A home satellite receiving systemas recited in claim 10, wherein the outdoor unit comprises a packetfilter to selectively filter data packets from inclusion in the singlebitstream.
 15. A home satellite receiving system as recited in claim 10,wherein the outdoor unit timestamps the data packets included in thesingle bitstream with a local time that can be used by the indoor deviceto reconstruct timing of streams of the data packets.
 16. A homesatellite receiving system comprising: a receiver to receive multiplesatellite signals; and an outdoor unit connected to the receiver todemodulate the satellite signals into multiple corresponding streams ofdata packets, the outdoor unit being configured to select data packetsfrom respective streams based on program identifiers that associate thedata packets with programs.
 17. A home satellite receiving system asrecited in claim 16, wherein the outdoor unit is configured to form asingle data stream containing the selected data packets from themultiple streams and modulate the single data stream for transmission toan indoor device.
 18. A home satellite receiving system as recited inclaim 16, wherein the outdoor unit timestamps the selected data packetwith a local time.
 19. In a satellite receiving system, an outdoor unitcomprising: multiple tuners to tune to different satellite signals;multiple demodulators, each demodulator being associated with acorresponding tuner to demodulate an associated signal received by thecorresponding tuner into a stream of data packets; multipledemultiplexers, each demultiplexer being associated with a correspondingdemodulator to select a subset of data packets from an associated streamof data packets output by the corresponding demodulator; multiplequeues, each queue being associated with a corresponding demultiplexerto store the subset of data packets selected by the correspondingdemultiplexer; a multiplexer to aggregate the data packets held in thequeues into a single data stream; and a remodulator to modulate thesingle data stream for local transmission.
 20. An outdoor unit asrecited in claim 19, wherein the demodulators employ a first modulationtechnique and the remodulator employs a second modulation techniquedifferent from the first modulation technique.
 21. An outdoor unit asrecited in claim 19, wherein each stream of data packets contains datapackets for one or more programs, the demultiplexers being configured toselect the subset of data packets according to program identifierscontained in the data packets, each program identifier identifying aprogram to which the data packet belongs.
 22. An outdoor unit as recitedin claim 21, further comprising a processor to provide the programidentifier to the demultiplexers in response to viewer selection of aprogram.
 23. An outdoor unit as recited in claim 19, further comprisinga processor to provide tuning control information to the tuners.
 24. Anoutdoor unit as recited in claim 19, further comprising a switch toconnect multiple satellite receiver connectors with the multiple tuners.25. An outdoor unit as recited in claim 19, further comprising multipletime stamping units, each time stamping unit being associated with acorresponding demultiplexer to time stamp the subset of data packetsselected by the corresponding demultiplexer.
 26. A home satellitereceiving system comprising: a satellite receiver; an indoor decodingunit; and the outdoor unit as recited in claim 19 coupled to thesatellite receiver and to the indoor decoding unit, the outdoor unitbeing connected to the indoor decoding unit via a single cable overwhich the single data stream is transmitted.
 27. In a satellitereceiving system, an outdoor unit comprising: tuning means for tuning tomultiple satellite signals; demodulating means for demodulating themultiple satellite signals into corresponding bitstreams; aggregatingmeans for forming a single bitstream from the multiple bitstreams; andmodulating means for modulating the single bitstream for transmission.28. An outdoor unit as recited in claim 27, wherein the demodulatingmeans and the modulating means employ different modulation schemes. 29.An outdoor unit as recited in claim 27, further comprising storage meansfor storing the bitstreams independent of one another, the aggregatingmeans integrating the bitstreams from the storage means to form thesingle bitstream.
 30. An outdoor unit as recited in claim 27, furthercomprising means for selecting content from the bitstreams to beincluded in the single bitstream based upon whether the content pertainsto one or more viewer-specified programs.
 31. A home satellite receivingsystem comprising: a satellite receiver; an indoor decoding unit; andthe outdoor unit as recited in claim 27, coupled to the satellitereceiver and to the indoor decoding unit, the outdoor unit beingconnected to the indoor decoding unit via a single cable over which thesingle bitstream is transmitted.
 32. In a satellite receiving system, anoutdoor unit comprising: tuning means for tuning to multiple satellitesignals; demodulating means for demodulating the multiple satellitesignals into corresponding streams of data packets, each stream of datapackets containing data packets for one or more programs; and selectingmeans for selecting a subset of data packets from the streams based uponwhich programs the data packets belong.
 33. An outdoor unit as recitedin claim 32, wherein each data packet has a program identifier toassociate the data packet with a program, and the selecting compriseschoosing the subset of data packets according to program identifiers inthe data packets.
 34. An outdoor unit as recited in claim 32, furthercomprising means for queuing the subset of data packets selected fromthe streams.
 35. An outdoor unit as recited in claim 32, furthercomprising: means for constructing a single data stream from the subsetof data packets selected by the selecting means; and modulating meansfor modulating the single data stream for transmission.
 36. A methodcomprising: tuning to multiple satellite signals; demodulating thesignals into respective streams of data packets; aggregating the datapackets from the respective streams into a single data stream; andmodulating the single data stream for local transmission.
 37. A methodas recited in claim 36, wherein the demodulating and the modulatingutilize different modulation schemes.
 38. A method as recited in claim36, further comprising selecting ones of the data packets from therespective streams for inclusion in the single data stream based uponprogram identifiers contained in the data packets.
 39. A method asrecited in claim 36, further comprising transmitting the single datastream over a single coaxial cable.
 40. In a satellite receiving systemhaving a receiver, an outdoor unit, and an indoor unit, a method foroperating the outdoor unit comprising: tuning to multiple satellitesignals; demodulating the signals into respective streams of datapackets, each stream of data packets containing data packets for one ormore programs; and selecting ones of the data packets from the streamsaccording to which programs the data packets belong.
 41. A method asrecited in claim 40, further comprising: forming a single data streamfrom the selected data packets; modulating the single data stream; andtransmitting the single data stream to the indoor unit.
 42. In asatellite receiving system having a receiver, an outdoor unit, and anindoor unit, a method for operating the outdoor unit comprising: tuningto multiple satellite signals being received by the receiver;demodulating the signals into respective streams of data packets;selecting subsets of the data packets from the respective streams;time-stamping the selected data packets with a local timestamp; queuingthe selected data packets in respective queues; forming a single datastream from the selected data packets stored in the queues; modulatingthe single data stream; and transmitting the modulated single datastream to the indoor unit.
 43. A method as recited in claim 42, whereinthe demodulating and the modulating utilize different modulationschemes.
 44. A method as recited in claim 42, wherein the selecting isbased on program identifiers contained in the data packets.
 45. A methodas recited in claim 42, wherein the timestamps are used by the indoorunit to reconstruct timing of the multiple streams of data packets. 46.A method as recited in claim 42, wherein the transmitting comprisestransmitting the data stream over a single coaxial cable.